Inhibitory effect of SDF-1 on the cycling activity of human HPP-CFCs and LTC-ICs in engrafted NOD/SCID mice.

Experiments are the same as those used to generate the data shown in Figure 1, but in this case, the values are the mean ± SEM of the percentage killed for each type of progenitor assessed after exposure of sorted human CD34⁺ cells to high–specific activity³H-thymidine either for 20 minutes (CFCs) or overnight (LTC-ICs). Data marked by asterisks indicate a significant difference from the corresponding control value (P < .001). The total colony counts in the control groups (no ³H-thymidine) ranged from 10 to 134.